DEVELOPMENT OF THE STOMACH. 



339 



there occurs a considerable obliquity of its axis, it soon 



assumes an oblique position. The upper end lies more to 



the left and the lower end more 



to the right. The anterior end 



extends so as to form the long 



narrow canal of the gullet 



{oesophagus) ; below the latter, 



the blind-sac of the stomach 



{fundus) bulges out to tlie left, 



and thus the later form of the 



stomach is gradually developed 



(Fig. 287, e ; Fig. 275, p. 317). The 



axis, which was originally verti- 



FiG. 287. — Human embryo of five 

 weeks, from the ventral side ; opened 

 (enlarged). The breast wall, abdominal 

 wall, and liverj have been removed. 3, 

 external nasal process ; 4, upper jaw ; 6, 

 lower jaw ; z, tongue ; v, right, v', left 

 ventricle of heart ; o', left auricle of 

 heart ; b, origin of aorta ; h' h" h'", Ist, 

 2nd, 3rd aorta-arches ; c c' c", hollow 

 vein ; ae, lungs {y, lung-arteries) ; e, 

 stomach ; m, primitive kidneys (j, left 

 yelk- vein ; s, pylorus ; a, right yelk- 

 artery ; n, navel-artery ; n, navel-vein) ; 

 X, yelk-duct ; i, terminal intestine ; 8, 

 tail; 9, fore-limb ; 9', hind-limb. (After 

 Coste.) 



cal, now inclines from a higher point on the left to a lowei' 

 on the right, and continually acquires a more transverse 

 direction. In the outer stratum of the stomach-wall, and 

 from the intestinal-fibrous layer, develop the strong muscles 

 which perform the powerful digestive movements. In 



